Heart failure is a leading cause of death in developed countries. An estimated 100,000 Americans develop end-stage congestive heart failure each year with a one-year mortality of approximately 50%. There are many etiologies of heart failure. Treatment options depend on the underlying cause and consist of drug therapy, catheter based or surgical interventions for coronary artery disease, and catheter or surgical procedures for valve disease and other lesions. In the past, the only treatment for end-stage non-correctable heart failure was heart transplantation. Approximately 2,000 heart transplant procedures are done annually in the United States and approximately 5,000 are performed annually world-wide. At any given time, there are approximately 3,000 patients on the heart transplant waiting list in the United States. Consequently, demand for transplantation far outstrips the supply of donor hearts, and it is unlikely that this supply imbalance will improve. Because of the donor supply imbalance, practitioners have developed mechanical systems to support the circulation in patients with heart failure at imminent risk of death.
These systems are known as ventricular assist systems (“VAS”) or more commonly as ventricular assist devices (“VAD”). A VAD implemented on the left side of the heart is referred to as a left ventricular assist device (“LVAD”), right side devices are referred to as right ventricular assist devices (“RVAD”s), and when applied to both sides of the heart these devices are referred to as “Bi-VAD”s. Initially, VAD therapy was limited to heart transplant candidates and was intended to buy time for these patients to survive to transplant and to improve their baseline health status going into transplant. This strategy is commonly referred to as Bridge to Transplant (“BTT”). As technology improved, VAD outcomes improved dramatically and VAD therapy was extended to the much larger population of heart failure patients who are not candidates for transplant. VAD treatment in the latter pool of patients with heart failure is referred to as Destination Treatment (“DT”).
Conventional LVADs include pulsatile devices that create a pulsed flow and non-pulsatile devices that provide continuous flow. Most current LVADs are continuous flow devices. The smaller continuous flow LVADs are placed within the pericardial space and do not require an intra-abdominal pocket. These devices generally employ a separate component, called an apical cuff, that is first attached to the left ventricular apex, and the pumping device is then attached to the apical cuff. Most conventional apical cuffs consist of a rigid metal cylinder surrounded by a fabric sewing ring.
Conventional installation methods for apical cuffs generally involve attaching the apical cuff to the left ventricular apex with surgically placed sutures that are brought through the sewing ring on the apical cuff. For example, a practitioner may utilize a plurality of horizontal mattress double-armed pledgeted sutures placed from the epicardial surface of the left ventricular myocardium toward the sewing ring on the apical cuff. Each needle is passed through the heart and then up through the sewing ring. After all sutures are placed, the sutures are successively tied resulting in knots on the sewing ring. After the apical cuff is attached to the heart, a core of left ventricular muscle is removed in the center of the apical cuff and the pump is mechanically fastened to the apical cuff. This conventional method/practice of placing pledgeted sutures is time consuming, and imperfections may result in significant bleeding complications.